1. Field of the Invention
The present invention relates to a sheet feeding apparatus for feeding a recording medium to a recording apparatus and an image forming apparatus having such a sheet feeding apparatus, and more particularly, it relates to mounting of the recording apparatus.
2. Related Background Art
Similar to many other equipments, compactness and light-weighted requirements for a recording apparatus (referred to as "printer" hereinafter) have been sought greatly, and, thus, printers have been made compact and light-weighted.
During realization of compactness, as disclosed in Japanese Patent Application Laid-open No. 6-183582, there has been proposed a technique in which a printer body portion for recording an image is separated from an auto sheet feeder (referred to as "ASF" hereinafter) portion (sheet feeding apparatus) for stacking sheets thereon and feeding the stacked sheets (recording media) one by one to an image forming portion of the printer, so that the ASF can be detachably mounted to the printer.
Further, there has also been proposed an ASF which can detachably be mounted, from outside, to a printer having a plurality of sheet feeding openings or a printer in which only manual sheet insertion is permitted, as well as the compact printer.
In such a conventional ASF, the ASF essentially has a concept that it is to be mounted to the printer, and, thus, the printer is a principal part on the desk exceedingly. That is to say, since the conventional ASF cannot perform a function for automatically feeding the sheet by itself only, the ASF can have any form. For example, the only ASF may not be operated by itself or may not be operated in a condition that recording media (referred to as "sheets" hereinafter) are set therein.
However, recently, a mobile field has been noticed to enhance maneuverability, and, thus, portable ability has been requested for printers. To this end, for the ASFs, there has been requested a function for connection to the portable printer on the desk in a more preferable condition, i.e., a function in which a so-called mobile printer having excellent portable ability can be used as a desk-top printer having excellent sheet feeding ability on the desk.
Further, in an ASF to be mounted to the printer from outside, for example, as disclosed in Japanese Patent Application Laid-open No. 4-303336, a drive transmitting means (such as a gear) exposed out of the ASF is connected to a drive transmitting means exposed out of the printer so that a motor disposed within the printer can be used as a drive source for a sheet feed roller for feeding the sheets one by one.
Further, in the ASF to be mounted to the printer from outside, for example, as disclosed in Japanese Patent Application Laid-open No. 9-194085, an apparatus incorporating therein a motor as a drive source for a sheet feed roller has been proposed. In this case, a control means disposed within the printer imparts a control signal to a motor disposed within the ASF through electric contacts between the printer and the ASF to rotate the motor of the ASF.
FIG. 39 is a perspective view showing a printer body of a printer 1000 disclosed in the above Japanese Patent Application Laid-open No. 4-303336 and an ASF to be mounted to the printer body from outside, in a separated condition.
The ASF 1047 has left and right hooks 1016, 1017 to be inserted into hook fitting holes 1103y, 1103z of the printer body 1101, and the left and right hooks 1016, 1017 can be rotated by sliding operation portions 1016c (only one is shown) provided on left and right side surfaces of the ASF 1047.
The left and right hooks 1016, 1017 inserted into the hook fitting holes 1103y, 1103z are rotated by sliding the left and right operation portions 1016c in directions shown by the arrows L1016X, L1017X to engage the ASF 1047 with the printer body 1101, thereby securing the ASF to the printer body.
The connection between the ASF 1047 and the printer body 1101 by means of the left and right hooks 1016, 1017 simultaneously produces connection of sheet paths 1056, 1101y and a gear 1047z constituting a sheet route between the ASF 1047 and the printer body 1101.
When the ASF 1047 is dismounted from the printer body 1101, the left and right hooks 1016, 1017 are rotated in directions opposite to the directions for engagement between the ASF 1047 and the printer body 1101 by sliding the left and right operation portions 1016c in directions opposite to the directions shown by the arrows L1016X, L1017X, thereby separating the ASF 1047 from the printer body 1101.
However, in such a mounting/dismounting mechanism between the printer body 1101 and the ASF 1047, the operator or user must pay attention to damage of positioning means and connectors (connection portions) in order to convey the sheet from the ASF 1047 to the printer body 1101 without any sheet jam.
Further, since the two hooks 1016, 1017 are independently rotated, the hooks 1016, 1017 must be rotated independently in order to separate the ASF 1047 from the printer body 1101, thereby worsening operability. Further, when the ASF 1047 is connected to the printer body 1101, it cannot be ascertained whether such connection is effected properly.
In addition, in such a mounting/dismounting mechanism between the printer body and the ASF, when the ASF is connected to the printer body, there arose a problem that a relative positional relationship becomes incorrect.
There also arose a problem that separation between the printer body and the ASF cannot be preformed smoothly.
Further, when the ASF is connected to the printer body by such a mounting/dismounting mechanism between, due to the relative positional error, the sheet cannot flow from the ASF to the printer body smoothly.
In addition, since the separation between the printer body and the ASF is not ensured completely, the printer body and/or the ASF may be damaged.